T7 lysome come from pLysS cause lysis?

[Yeon Chul Kim]

Hi!!

We performed fed-batch fermentation using pLysS containg E. coli.
After IPTG induction, we acheived ca 90 g/L of DCW.  But a lots of
cells are lysed.   I think cell lysis is common problem in high cell
density.  But, I also wonder the T7 lysome produced by pLysS cause
lysis.  In some reference, relatively high levels of T7 lysome can be
tolerated by E. coli, because the protein is unable to pass through
the inner membrane to reach the peptidoglycan layer.  But,  I think,
in high cell density, cells are not in normal conditions.  So, the T7
lysome enhance the cell lysis.
Do you have any comment?
Or Do you have some reference about pLysS plasmid (especially, amount
of T7 lysome produced, effect on cell lysis.)

Thank you.

Yeon Chul Kim


Yeon Chul Kim

BPERC, KAIST, 373-1, Kusong-dong,
Yusong-gu, Taejon 305-701, Korea

Tel)    82-42-869-3952
Fax)    82-42-869-8800
E-mail) e_yckim at cais.kaist.ac.kr
URL)    http://chiak.kaist.ac.kr/~yckim